91920931 has 8 divisors (see below), whose sum is σ = 93852000. Its totient is φ = 90007680.

The previous prime is 91920883. The next prime is 91920953. The reversal of 91920931 is 13902919.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 91920931 - 2²¹ = 89823779 is a prime.

It is a super-2 number, since 2×91920931² = 16898915111813522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91920991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6235 + ... + 14923.

It is an arithmetic number, because the mean of its divisors is an integer number (11731500).

Almost surely, 2^91920931 is an apocalyptic number.

91920931 is a deficient number, since it is larger than the sum of its proper divisors (1931069).

91920931 is a wasteful number, since it uses less digits than its factorization.

91920931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8909.

The product of its (nonzero) digits is 4374, while the sum is 34.

The square root of 91920931 is about 9587.5404040870. The cubic root of 91920931 is about 451.3063783172.

The spelling of 91920931 in words is "ninety-one million, nine hundred twenty thousand, nine hundred thirty-one".